Katy Perry — Twitter’s most followed human — is prepping for the Super Bowl’s halftime show. What’s on her agenda? Checking her dancer’s cleavage (“too much”), texting with Bruno Mars (“Hello, Super Bowl club member!”) and letting a little trash talk slip regarding a certain crossover diva (“If somebody defames my character, you’re going to hear about it”).

Says Charli XCX, who will be opening for Perry this spring: “She makes sugary, plastic pop so well, makes it sound smart and amazing. But she also has such a vision within her videos and her live show. I love that she goes all the way with it.”

“I grew up in a little bit of a bubble of ­ignorance and judgment and so I’m happy that I’ve been able to evolve past that,”  Perry says.

Her dream? “My own Starbucks on the property,” she says, only half-joking. “I have to create my own world because it’s hard to go into the other world sometimes. Barbra Streisand has a mall downstairs in her basement — just weird, amazing stuff like that. I get it, because it becomes such a thing to go out in the world.”

“Everyone has been asking me if I’m going to be nervous before the halftime show,” Perry says about headlining the Super Bowl halftime show. “I’m like, I’m f—ing human. This is the biggest event of my career.”